Is there any shuffling algorithm in PHP optimized for large arrays?

For large arrays containing a large number of elements, the Fisher-Yates Shuffle algorithm can be used to efficiently shuffle the order and achieve an efficiency optimization with a time complexity of O(n).

Shuffle order algorithm optimized for large arrays in PHP

Introduction

For large arrays containing a large number of elements, using the regular shuffle algorithm may be inefficient. PHP provides a specialized algorithm optimized for large arrays that can be used to efficiently shuffle the order of elements in an array.

Fisher-Yates Shuffle algorithm

The shuffle() function in PHP implements the Fisher-Yates Shuffle algorithm. This algorithm implements shuffling by repeatedly exchanging randomly selected elements in the array, and has a time complexity of O(n), where n is the size of the array.

Code

<?php

// 创建包含大量元素的大数组
$array = range(1, 100000);

// 使用 Fisher-Yates Shuffle 算法打乱数组顺序
shuffle($array);

// 输出打乱后的数组
echo '<pre class="brush:php;toolbar:false">';
print_r($array);
echo '

';

Practical case

Assume we have a large array containing 100,000 order IDs, we need Orders are randomly selected for processing. We can use the Fisher-Yates Shuffle algorithm to select orders efficiently:

<?php

// 获取包含 10 万个订单 ID 的数组
$orders = range(1, 100000);

// 打乱订单 ID 的顺序
shuffle($orders);

// 随机选择 10 个订单 ID
$selectedOrders = array_slice($orders, 0, 10);

By using the shuffle() function, we can select orders efficiently and avoid traversing the entire array to select random elements.

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